Assembly Matrix
Manual Transmission Gears Parts 2025
Overview of assemblies, gear compatibility, spline types, and roller configurations.
‘Syracuse’ M20: The Wide-Ratio Benchmark
The Muncie M20 is a smooth-shifting, wide-ratio 4-speed — engineered for street cruising, restorations, and lighter builds. With global-quality components and AutoGear durability, it’s a modern classic ready for the road.
Whether you’re building a daily driver, a classic cruiser, or a period-correct muscle car, the M20 brings effortless shifts and long-lasting performance — all in the original Muncie footprint.
Why Choose the M20?
✅ Smooth, predictable RPM drop between shifts
✅ Supercase standard with 9310-equivalent countershaft
✅ OEM-friendly install footprint for easy retrofits
✅ Durable, quiet operation for road use
✅ Ideal for lighter builds or street-first restorations
Gear Ratio Packages
| Model | 1st Gear | 2nd Gear | 3rd Gear | 4th Gear | Best For |
|---|---|---|---|---|---|
| M20 | 2.521 | 1.880 | 1.461 | 1.00 | Street cruising & lighter loads |
Additional ratio codes available (314, 324, etc.) — Contact us to find your match.
Resources
View documents and resources related to this gearbox in the resource center.
View ResourcesThe Complete Guide
AutoGear Gearbox & Gearset Option Codes
Overview of assemblies, gear compatibility, spline types, and roller configurations.